The present invention is a slip spline seal assembly for sealing the ends of a splined yoke shaft and complementary sleeve. Although suitable for the vehicular field, the invention has application with any spline type seal such as typically found in all types of drive shafts and in the machine tool industry.
Seal assemblies for spline shafts are known in the art. However, such assemblies suffer from their inability to be lubricated, especially along and about their sealing surfaces. This disadvantage is important with respect to seal assemblies made from compressible or flexible materials, since the lack of lubrication eventually results in deterioration of those materials. The spline projections or teeth on such assemblies then become susceptible to disintegration. The effects of disintegration are magnified with seal assemblies which are designed to seal the connection between a splined shaft and sleeve, and yet slip along the shaft with such sleeve. The slipping action, under those circumstances, causes the spline projections or teeth of the assembly to break off, thereby limiting their useful life and requiring frequent replacement of the assembly. The consequent loss in sealing ability further promotes wear of the splined shaft itself.
An additional disadvantage of the prior art assemblies, especially those designed for splined shaft and sleeve combinations, is their lack of a means for displacement of the flexible material when the flexible assembly projections are compressed. Consequently, the projections fit too tightly against the ribs of the shaft and are subject to additional excessive stress, wear and tear.